When trying to place upgrade order from Customer Control Panel the following error appears:
Request-URI Too Large The requested URL's length exceeds the capacity limit for this server. Apache/2.2.15 (CentOS) Server at server_name Port 443
If customer clicks on Account tab after that, real error displayed:
The valid payment method should be selected.
Customer tries to place resource upgrade order without payment method selected. In Resource upgrade wizard in Payment Methods drop down list --SELECT-- option is selected by default.
Bug #PBA-46323 was created to show correct error.
The issue is fixed in PBA-E 5.4.16. Please upgrade to the latest version of PBA-E.
Please note that customer should select one of the available payment methods before placing order.